The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1887-04-28
COLL1ERY EXPLOSIONS.
Efforts Which Have Been Made
aa to Prevent Them. &{A
The 4Davyv Lamp and Fire Damp-Coal
Dust tDangers-'Shot-Fir Firing" to Give
Place to-Safer Methods 81
Explosions.


sAsaks rzM .sgz wssg gsm =
The atmosphere, of every coal-mine
probably contains more or less marsh
gas although in some the amount is so
yery small that the air within them
could never become explosive under or
binary conditions of working. There
isno doubt that gas frequently escapes
detection owing to the imperfection of
the means employed for its recognition.
If present in certain proportions the
marsh gas is revealed by the elonga-
ton of the fame Of the safety-lamp, or
by the appearance of what is
known as a "cap" upon the fame.
An experienced eye can determine pret-
ty accurately the relative amount of
thefire-damp from the size and character
Of the cap upon properly trimmed
flame; but thetest altogether fails when
the proportion of gas falls below two
per cent. This amount, small as it may
seem, may, under certain circum-
stances, prove highly dangerous. The
mine-manager and the .'firemen" re-
quire to use some more delicate method
Of detecting small quantities of fire.
damp than that usually employed. For
tunately such methods are notunknown.
Mr. Liveing has devised very ingeni-
! ons indicator, by which the existence
of marsh gas can be detected and it's
amount estimated even when the guam
tity is as low as a quarter per cent.
Two precisely similar pieces of thin
Flatlnul wire are simultaneously
heated to bright redness by the action
Of small magneto-electric machine
worked by hand. One of the wires is
contained in small tube filled with pure
air; the other can be surrounded at will,
and in minute or two, with air
from any part of the mine. If fire.
damp is present it burns round the hot
wire, which is thereby increased in
temperature and emits more brilliant
light. BY comparing the intensities of
the light emitted by the two wires by
The aid OF a very simple photometric
arrangement the percentage amount of
flre-damp present may be at once de-
termined. The apparatus is portable
and easily worked, and is well adapted
for use under ground.
Seventy years have elapsed since Sir
Humphrey Davy invented the safety
lamp which is associated with his name.
It's almost impossible to oyerestimate
tle influence of that invention in the
Development of eoal-niining g-inthe de-
selopment, indeed, of our national
prosperity. 1t has. unquestionably
saved thousands of lives, and has en-
abled millions of tons of coal to be
raised which, without it, could not pos
slDly have been won. -.
Itis related that when Mr.. Buddle,
snese name is well known in the
history Of coal-mining for the
improvements he introduced into
.he system of ventilating collieries,
.ook down one of the first Davy. lamps
.ll'o fery pit and beheld the fire-damr
cap playing round the light and ap.
pan6ntiv Imprisoned within the wire.
saaze cylinder, he exclaimed exult.
iasiys = eAt last we have subdued this
monsterr,
4soe year passes, however, without
@ us monster showing us that he il
s.''l very far from subsection; and
s.lange to say, the Davy lamp itsel1
sae the very system of ventilation
sa'en we owe to Mr.. Buddle, rs de
'eloped in these later times, have con
spaed to aid the monster in his work
" nayoe and disaster.
now this has come about NAV bt
,ola Y e very few words. When the
.s'ap was first introduced the yentilat
.s currents in mines seldom exceeded :
s.oei'y OF three hundred feet pei
rsm a',e IN the air-ways, and they were
Usually .a rerys feeble in the working
@ f'aees. Nowadays the enormous fan.
~ osaer mechanical ventilators whicl
~, = e.npioyed cause the air to travel a
=. ueieies approaching two thousand
rsa,l Re. minute nthe air-ways, and cur
m; ass q more than four hundred feet pei
: a.e - are not anfrequently met will
ne working places. Under thes,
lsssa l'''ons the Davy lamp and. in
iar1 @ oegree, two other well-knowr
a. = ]. @. @ safety lamp-the Clanny ant
.ls.. stephenson lamps-become al,so
skttIf unsafe in ar